Electrospinning is a technology that is very promising for fabricating tissue scaffoldings, particularly those intended for blood vessels. Here we have presented strong preliminary data demonstrating the feasibility and innovation of spinning collagen and other matrix materials into the appropriate geometry for cell seeding. Traditional graft materials are prone to infection and thrombosis particularly when used for small vessel reconstructions. Thus, there is a large and growing need for better conduit materials. This project will help us to bring a biological alternative to prosthetic grafts to the clinic. With its combination of a unique scaffold system, in vivo evaluation, and bioreactor development, successful completion of this project will result in a fundamentally new approach to vascular replacement with potential to change the paradigm for vascular replacement, and address the need for the almost 1.4 million arterial replacements performed per year. Project Narrative This project aims to generate a scaffold for vascular graft replacement using electrospun biological polymers. The scaffold will be developed and cultured with vascular cells in a bioreactor capable of controlled pulsatile flow. The scaffold will be evaluated in an in vivo rabbit abdominal aorta replacement model.